Transcript Lecture 11
Building Trustworthy Semantic Webs Lecture #11: Ontology Engineering Dr. Bhavani Thuraisingham September 25, 2006 4/11/2016 02:06 11-2 Objective of the Unit 0 This unit will provide an overview of the software engineering aspects of ontologies. The field is called Ontology Engineering 4/11/2016 02:06 11-3 Outline of the Unit 0 Summary of semantic web technologies discussed so far 0 Applications discussed so far 0 Ontology Engineering 0 Directions 4/11/2016 02:06 11-4 Semantic web technologies discussed so far 0 XML, XML Schema 0 RDF, RDF Schema 0 Ontology, OWL 0 Logic, Rules, Inference 0 Some discussion of security issues for each technology - Policy specification, Securing documents 4/11/2016 02:06 11-5 Types of Application 0 Horizontal Information Products at Elsevier: Integration 0 Data integration at Audi: Integration 0 Skill finding at Swiss Life: Search 0 Think Tank Portal at EnterSearch: Knowledge man agent 0 E-Learning: Knowledge management 0 Web Services: Web services (for any of the other applications discussed) 0 Multimedia Collection at Scotland Yard: Searching 0 Online Procurement at Daimler Chrysler: E-Business 0 Device Interoperability at Nokia: Interoperability 4/11/2016 02:06 11-6 Revisiting Ontology 0 Common definitions for any entity, person or thing 0 Several ontologies have been defined and available for use 0 Defining common ontology for an entity is a challenge 0 Mappings have to be developed for multiple ontologies 0 Specific languages have been developed for ontologies - RDF, OWL, DAML+OIL, etc. 4/11/2016 02:06 11-7 What is Ontology Engineering? 0 Tools and Techniques to - Create Ontologies - Specify Ontologies - Maintain Ontologies - Query Ontologies - Evolve Ontologies - Reuse Ontologies - Incorporate features such as security, data quality, integrity 4/11/2016 02:06 11-8 Manual Constructiob of Ontologues 0 Determine Scope 0 Consider Reuse 0 Enumerate Terms 0 Define Taxonomy 0 Define Properties 0 Define facets 0 Define Instances 0 Check for Anomalies 4/11/2016 02:06 11-9 Reuseing Exitsing Ontologies 0 The goal is not to reinvent the wheel 0 Several ontologies have been developed for different domains 0 Codieid Bodies of Expert Knowledge 0 Integrated Vocabularies 0 Upper Level Ontologies 0 Topic Hierarchies 0 Linguistic Resources 0 Ontology Libraries 4/11/2016 02:06 11-10 Semi/Automatics Methods for Ontology Generation 0 Much of the research is focusing on developing ontologies 0 0 0 0 using tools from multiple heterogeneous data sources Essentially extracting concepts and expanding on concepts from the data sources Uses combination of data integration, metadata extraction, and machine learning techniques E.g. Clustering of concepts, Classification of concepts etc. Text Book describes Semantic Web Knowledge Management Architecture 4/11/2016 02:06 11-11 What is Knowledge Management? 0 Knowledge management, or KM, is the process through which organizations generate value from their intellectual property and knowledge-based assets 0 KM involves the creation, dissemination, and utilization of knowledge 0 Ontologies are a form of Knowledge? 0 Reference: http://www.commerce-database.com/knowledge- management.htm?source=google 4/11/2016 02:06 11-12 Directions 0 Need tools for developing semantic web technologies - XML documents, RDF documents, Ontologies, etc. 0 How to integrate the multiple ontologjes and tools? 0 Role of Agents – agents are processes that reasons with semantic web technologies 0 Semantic web services, data mining, knowledge management integrated